1. Field of the Invention
The present invention relates to mobile pipe lining apparatuses and more specifically, to an apparatus for installing strip lining material into a host pipe.
2. Discussion of the Background
Over time, pipes, particularly larger buried pipes, such as sewer lines, will naturally deteriorate. Replacing them can be extraordinarily expensive. Instead, techniques have been developed to reline the interior of the pipe so that it does not have to be dug up and replaced. Machines devised for sewer pipe relining are described in U.S. Pat. Nos. 6,663,319; 5,954,903; 6,089,279 and 7,186,060 (incorporated herein by reference). Generally, in tubular culverts, a self-propelled pipe manufacturing apparatus with a revolving motion is used to form a tubular body by spirally winding and locking together a continuously supplied elongated strip lining material into the interior of the old pipe to form a new lining.
However, these pipe manufacturing apparatuses cannot effectively keep a stable/constant center line movement as the lining machine walks down the pipe because the lining machine cannot adapt to the variable contours (bends) of different sewer pipes, and obstacles such as deformities in the pipe wall. Therefore, it is difficult to create a consistent pipe lining in a curved sewer pipe or pipe with variable contours. Moreover, the force of the feed material being fed into the lining machine causes the lining machine to walk in direction of the forming motion and away from centerline. This can cause liner riblocks of the strip lining material to pull apart, and/or get caught on the inner surface of the pipe being restored, among other issues.
In addition, larger pipes necessitate a larger, heavier lining machine, and the weight of the lining machine can cause damage to the plastic strip liner (cracking, locks pulling apart, etc.), the sewer pipe, as well as damage to the weight bearing components of the lining machine itself. Therefore, as pipe diameters increase, it becomes impractical to drive the strip lining material from the end of the pipe to the relining site as the distance increases. In other words, “pushing” the relining down the pipe becomes impossible as the weight increases. The strip lining material's own weight becomes a problem as does the frictional interaction with the pipe, among other issues.